DYNASCORE: DYNAmic Software COntroller to increase REsource utilization in mixed-critical systems

International audienceIn real-time mixed-critical systems, Worst-Case Execution Time analysis (WCET) is required to guarantee that timing constraints are respected —at least for high criticality tasks. However, the WCET is pessimistic compared to the real execution time, especially for multicore platforms. As WCET computation considers the worst-case scenario, it means that whenever a high criticality task accesses a shared resource in multi-core platforms, it is considered that all cores use the same resource concurrently. This pessimism in WCET computation leads to a dramatic under utilization of the platform resources, or even failing to meet the timing constraints. In order to increase resource utilization while guaranteeing real-time guarantees for high criticality tasks, previous works proposed a run-time control system to monitor and decide when the interferences from low criticality tasks cannot be further tolerated. However, in the initial approaches, the points where the controller is executed were statically predefined. In this work, we propose a dynamic run-time control which adapts its observations to on-line temporal properties, increasing further the dynamism of the approach, and mitigating the unnecessary overhead implied by existing static approaches. Our dynamic adaptive approach allows to control the ongoing execution of tasks based on run-time information, and increases further the gains in terms of resource utilization compared with static approaches